1. Field of the Invention
The present invention relates to enclosures for portable electronic devices, and particularly to a one-piece metal enclosure for a portable electronic device and a method for forming the enclosure.
2. Related Art
With constant development of information technology, portable electronic devices such as mobile phones and personal digital assistants (PDAs) have become very popular. These devices each have an enclosure for accommodating and supporting electronic components therein. The enclosure can be made of plastic material or metallic material. Plastic material has many advantages such as low weight, low cost, ease of manufacture, and corrosion-resistance. However, plastic material is relatively fragile, and does not provide good protection from electromagnetic interference (EMI).
An enclosure made of metallic material is strong and provides superior EMI protection. A conventional metal enclosure comprises a front cover and a rear base that are connected together at mechanical joints. Gaps are defined between the cover and the base, which reduce EMI protection. In addition, the cover and the base are liable to be dislodged from each other when the enclosure is subjected to shock. Furthermore, assembly of the cover and the base is unduly laborious. A conventional metal enclosure is disclosed in U.S. Pat. No. 6,229,993. The enclosure includes a front cover and a rear base which are joined at overlapping portions thereof. A skirt portion around a periphery of the front cover is shaped to receive and overlap a peripheral edge of the rear base, to thereby form the enclosure. However, a small gap still exists between the front cover and the rear base.
An improved enclosure that overcomes the above-mentioned problems of the related art is desired.